Recently, smart devices equipped with a touch function have been popularized, and various chat applications to be used with such smart devices have been released. Most chat applications mainly include inputting characters using a character input module provided by a user terminal, and include a function of selecting and displaying predetermined static or dynamic images. Such conventional chat applications use a predetermined image to display a user's emotions or the like, so that contents that can be input are limited and a degree of freedom is decreased.
In consideration of such a problem, there have been proposed methods to communicate emotions and the like to a chatting party. Even in the case that a user manually inputs handwriting, in this way, only one user can display directly written text or a drawn picture to another user. An example of a chat application that sends a user's handwriting to another user by chatting is Korean Patent No. 10-1597819 (Registered on Feb. 19, 2016; “PAINT CHAT DEVICE BETWEEN COMMUNICATION TERMINALS”).
The above-mentioned patent discloses a technique of placing a picture input field area on a touch screen, image the input picture or text and send the image to the user terminal of the chatting party. The image at this time can be synthesized according to the user's intention. However, the contents of the above mentioned registered patent do not allow a plurality of chat participants to chat together while drawing pictures, since the process of drawing pictures is unknown, there is a problem that it is not easy to accurately understand the user intention to be transmitted by the picture.
The above mentioned registered patent allows pictures to be drawn and sent by the chatting party, but there is no way to search for specific pictures received in previous chats in the future, so it may be difficult to search for pictures that were sent in previous chats.